A smoker has a cigarette in 2009 in Hudson, Wis. / Karen Bleier, AFP/Getty Images

by Hoai-Tran Bui, USA TODAY

by Hoai-Tran Bui, USA TODAY

Researchers found in a study released Tuesday that combining nicotine patches and the prescription medicine varenicline was more effectivein helping participants quit smoking than using varenicline by itself. The study, published in the medical research journal JAMA, found that participants who received active nicotine replacement therapy - or nicotine patches - and varenicline were more likely to abstain from smoking for up to six months.

"We found that in relatively healthy smokers, the odds of achieving successful smoking cessation after 12 and 24 weeks were significantly increased by using a combination of varenicline and nicotine patches compared to varenicline alone," said Coenraad Koegelenberg, the author of the study and a professor at the University of Stellenbosch in Cape Town, South Africa.

Varenicline is a smoking cessation medication that blocks the pleasant effects of nicotine from the brain - which include feelings of relaxation, sharpness and calm. Varenicline and bupropion are common medications to help people quit smoking that are licensed for use in the USA, Koegelenberg said.

Varenicline was used in the study because it is the most effective prescription medicine for quitting smoking, Koegelenberg said. Compared with using nicotine replacement therapy by itself, varenicline has helped 50% more people quit, according to Koegelenberg.

The researchers randomly assigned 446 smokers in South Africa either a nicotine patch and varenicline treatment or a placebo patch and varenicline. Treatments were continued for 12 weeks after the target quit date, and the researchers checked in with the participants at 24 weeks and six months. The study found that 65.1% of the varenicline-and-nicotine group abstained from smoking after six months compared with 46.7% in the placebo group.

The study was the "largest study to date examining the efficacy and safety of supplementing varenicline treatment with (nicotine replacement therapy)," Koegelenberg said.

The study used only nicotine patches, but Koegelenberg said future research could focus on combining other forms of nicotine replacement therapy such as gum or lozenges. Koegelenberg said he has seen patients frequently combine nicotine patches and gums but is unsure of any negative side effects of combining different drugs.

"The combination (of varenicline and nicotine patches) appears to be safe, although further studies are needed to confirm this," Koegelenberg said.

The two treatment groups experienced a variety of side effects, none of them adverse, Koegelenberg said. In the combined treatment group, more nausea, sleep disturbance, skin reactions, constipation and depression were reported; the varenicline-only group experienced more abnormal dreams and headaches.

Koegelenberg suggested that future research include a broader range of smokers and "assess the tolerability and cost-benefit comparisons with alternatives."